Heat pipe



FIG. 1 is a perspective view of a heap pipe showing my design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a left view thereof;

FIG. 5 is a right view thereof;

FIG. 6 is a front view thereof;

FIG. 7 is a rear view thereof;

FIG. 8 is a perspective view thereof in which the heat pipe is shown in a position of use located in a base; and,

FIG. 9 is a perspective view thereof in which the heat pipe is shown in a second position of use located in a heat sink.

The broken lines in FIGS. 8 and 9 represent environmental subject matter and form no part of the claim. 

The ornamental design for a heat pipe, as shown and described. 